Pipeline leak detection system

Abstract

A system for detecting leaks in a pipeline includes an outer containment pipe or jacket surrounding a pipe and defining an interstitial space therewith. A plurality of zone fittings are disposed within the containment pipe or jacket to divide the interstitial space into a plurality of zones. Individual external sensors are attached to the containment jacket at each of the zones for detecting the presence of fluid leakage into the interstitial space. The sensors generate an output signal which is operatively connected to visual and/or audible alarms.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A system for detecting leaks in a pipeline, said system comprising: an outer containment pipe surrounding said pipeline and defining an interstitial space therewith;   a plurality of dividers disposed within said containment pipe for dividing said interstitial space into a plurality of zones;   a plurality of external sensors attached to said containment pipe at each of said zones for detecting the presence of a fluid contained within said pipeline which has leaked into the interstitial space of one of said zones;   a well joined to said containment pipe within one of said zones, one of said sensors being attached to said well; and   output means operably connected to said sensors for providing an indication of the detection of a leak by any one of said sensors.   
     
     
       2. A system as defined by claim 1 wherein each of said sensors comprises: a saddle-shaped attachment bracket configured to partially surround said containment pipe.   
     
     
       3. A system as defined by claim 2 wherein each of said sensors further comprises: an adjustable capacitive proximity switch mounted on said attachment bracket, said switch generating an output signal when the fluid to be detected leaks into said interstitial space.   
     
     
       4. A system as defined by claim 1 wherein said output means comprises: a logic circuit operatively connected to said sensors   visual indicators operatively connected to said logic circuit; and   an audible indicator operatively connected to said logic circuit, each of said visual indicators being associated with one of said zones.   
     
     
       5. A system as defined by claim 1 wherein said containment pipe is fabricated from a nonmetallic material. 
     
     
       6. A system as defined by claim 5 wherein said well is fabricated from a clear section of pipe permitting a visual inspection. 
     
     
       7. A system as defined by claim 6 further comprising: a drip leg joined to said containment pipe;   an inner pipe disposed within said drip leg and connecting with said interstitial space so that fluid within said space will drain into Said inner pipe;   a riser joined to said drip leg at a lower end thereof; and   a sensor extraction member disposed within said riser, one of said sensors being connected to said extraction member, said one of said sensors being positioned on said inner pipe for detecting the presence of fluid in said inner pipe.   
     
     
       8. A system as defined by claim 1 wherein each of said sensors comprises a saddle-shaped attachment bracket configured to partially surround said containment pipe. 
     
     
       9. A system as defined by claim 8 wherein each of said sensors further comprises an adjustable capacitive proximity switch mounted on said attachment bracket, said switch generating an output signal when the fluid to be detected leaks into said interstitial space. 
     
     
       10. A system for detecting leaks in a pipeline, said system comprising: an outer containment pipe surrounding said pipeline and defining an interstitial space therewith;   a plurality of dividers disposed within said containment pipe for dividing said interstitial space into a plurality of zones;   a plurality of external sensors attached to said containment pipe at each of said zones for detecting the presence of a fluid contained within said pipeline which has leaked into the interstitial space of one of said zones;   each of said sensors including a saddle-shaped attachment bracket configured to partially surround said containment pipe and an adjustable capacitive proximity switch mounted on said attachment bracket, said switch generating an output signal when the fluid to be detected leaks into said interstitial space;   output means operably connected to said sensors for providing an indication of the detection of a leak by any one of said sensors; and   a well joined to said containment pipe within one of said zones, one of said sensors being attached to said well.   
     
     
       11. A system as defined by claim 10 further comprising: a drip leg joined to said containment pipe;   an inner pipe disposed within said drip leg and connecting with said interstitial space so that fluid within said space will drain into said inner pipe;   a riser joined to said drip leg at a lower end thereof; and   a sensor extraction member disposed within said riser, one of said sensors being connected to said extraction member, said one of said sensors being positioned on said inner pipe for detecting the presence of fluid in said inner pipe.   
     
     
       12. A system for detecting leaks in a pipeline, said system comprising: an outer containment pipe surrounding said pipeline and defining an interstitial space therewith;   a plurality of dividers disposed within said containment pipe for dividing said interstitial space into a plurality of zones;   a plurality of external sensors attached to said containment pipe at each of said zones for detecting the presence of a fluid contained within said pipeline which has leaked into the interstitial space of one of said zones;   a drip leg joined to said containment pipe;   an inner pipe disposed within said drip leg and connecting with said interstitial space so that fluid within said space will drain into said inner pipe;   a riser joined to said drip leg at a lower end thereof;   a sensor extraction member disposed within said riser, one of said sensors being connected to said extraction member, said one of said sensors being positioned on said inner pipe for detecting the presence of fluid in said inner pipe; and   output means operably connected to said sensors for providing an indication of the detection of a leak by any one of said sensors.   
     
     
       13. A system for detecting leaks in a pipeline, said system comprising: an outer containment pipe surrounding said pipeline and defining an interstitial space therewith;   a plurality of dividers disposed within said containment pipe for dividing said interstitial space into a plurality of zones;   a plurality of external sensors attached to said containment pipe at each of said zones for detecting the presence of a fluid contained within said pipeline which has leaked into the interstitial space of one of said zones;   a well joined to said containment pipe within one of said zones, one of said sensors being attached to said well; and   output means operably connected to said sensors for providing an indication of the detection of a leak by any one of said sensors, said output means including a logic circuit operatively connected to said sensors, visual indicators operatively connected to said logic circuit, each of said visual indicators being associated with one of said zones; and an audible indicator operatively connected to said logic circuit.   
     
     
       14. A nonintrusive external leak detection system for a double containment pipeline having an inner pipe and an outer containment pipe, said system comprising: a plurality of dividers configured to be positioned within the pipeline to divide the containment pipe into a plurality of zones;   a nonpenetrating density sensor assembly attachable to the pipeline at one of said zones, said sensor assembly being responsive to a change in density of material aligned therewith in said containment pipe in order to generate an output signal when a fluid to be detected enters said one of the zones; and   alarm means operatively connected to said sensor assembly for generating an alarm in response to said output signal.   
     
     
       15. A leak detection system as defined by claim 14 wherein said dividers each include an annular ring having an outer diameter substantially corresponding to the inner diameter of said outer containment pipe and a center aperture dimensioned to receive said inner pipe. 
     
     
       16. A leak detection system as defined by claim 15 further comprising a well adapted to be connected to and depend from the outer containment pipe, said well including a pipe segment, a cap joined to said segment and a drain valve joined to said cap. 
     
     
       17. A leak detection system as defined by claim 16 further comprising another external sensor operably connected to said alarm means and adapted to be mounted on said pipe segment of said well. 
     
     
       18. A leak detection system as defined by claim 15 further comprising: a drip leg including a vertical pipe section and a generally horizontal pipe section;   a collection pipe within said drip leg adapted to be connected to one of said zones;   a riser connected to the horizontal pipe section;   an extractor within said riser; and   a further sensor assembly on said extractor and engaging said collection pipe.   
     
     
       19. A leak detection system as defined by claim 18 further comprising a well adapted to be connected to and depend from the outer containment pipe, said well including a pipe segment, a cap joined to said segment and a drain valve joined to said cap. 
     
     
       20. A leak detection system as defined by claim 19 further comprising another external sensor operably connected to said alarm means and adapted to be mounted on said pipe segment of said well. 
     
     
       21. A nonintrusive external system for detecting leaks in a liquid pipeline comprising: an outer containment pipe surrounding a liquid pipeline and defining an interstitial space therewith;   a nonpenetrating sensor applied externally to said containment pipe and responsive to a change in density of material within said containment pipe adjacent said sensor in order to produce an output; and   a control responsive to a change in said output in order to produce an indication of the presence of a liquid in said containment pipe.   
     
     
       22. The system as defined in claim 21 wherein said outer containment pipe includes a low portion lower than other portions of said interstitial space and wherein said sensor is applied to said containment pipe at said low portion. 
     
     
       23. The system as defined in claim 21 wherein said containment pipe is fabricated from a nonmetallic material. 
     
     
       24. The system in claim 21 including a drip leg joined to said containment pipe, an inner pipe disposed within said drip leg and connecting with said interstitial space so that fluid within said space will drain into said inner pipe, and a riser pipe joined to said drip leg at a lower end thereof, wherein said sensor is applied within said riser on said inner pipe for detecting liquid in said inner pipe.